In an attempt to respond to the current stakes in business, Human Resource Departments regularly propose new management tools supposed to favour the involvement of staff and develop their effectiveness. An analysis of the effects of these tools shows that they are more often effective but that the dynamic effect is often short-lived. This article nourishes reflection on this phenomenon by developing the idea that the dynamic analysis of the use of management tools helps better to understand the dynamics of the development of HR polices of a business. A review of the literature indeed shows that an analysis of HR policies very often under-estimates the role that management tools play in this case. After having specified and analysed the requirements of this role, this article presents a case study which helps to identify the initial elements of an analytical framework of the dynamics of a management tool and proposes solutions in an attempt to remedy the fact that the HR policy it is intended to develop rapidly runs out of steam.